diff --git a/wsme/rest/json.py b/wsme/rest/json.py
index 898c5a0..5aa0ed5 100644
--- a/wsme/rest/json.py
+++ b/wsme/rest/json.py
@@ -11,6 +11,7 @@ from simplegeneric import generic
 
 from wsme.types import Unset
 import wsme.types
+from wsme.exc import UnknownArgument
 
 try:
     import simplejson as json
@@ -191,68 +192,6 @@ def datetime_fromjson(datatype, value):
     return datetime.datetime.strptime(value, '%Y-%m-%dT%H:%M:%S')
 
 
-class RestJson(object):
-    """
-    REST+Json protocol.
-
-    .. autoattribute:: name
-    .. autoattribute:: dataformat
-    .. autoattribute:: content_types
-    """
-
-    name = 'json'
-    content_type = 'application/json'
-
-    #def __init__(self, nest_result=False):
-    #    super(RestJsonProtocol, self).__init__()
-    #    self.nest_result = nest_result
-
-    def decode_arg(self, value, arg):
-        return fromjson(arg.datatype, value)
-
-    def parse_arg(self, name, value):
-        return json.loads(value)
-
-    def parse_args(self, body):
-        raw_args = json.loads(body)
-        return raw_args
-
-    def encode_result(self, context, result):
-        r = tojson(context.funcdef.return_type, result)
-        if self.nest_result:
-            r = {'result': r}
-        return json.dumps(r)
-
-    def encode_sample_value(self, datatype, value, format=False):
-        r = tojson(datatype, value)
-        content = json.dumps(r, ensure_ascii=False,
-            indent=4 if format else 0,
-            sort_keys=format)
-        return ('javascript', content)
-
-    def encode_sample_params(self, params, format=False):
-        kw = {}
-        for name, datatype, value in params:
-            kw[name] = tojson(datatype, value)
-        content = json.dumps(kw, ensure_ascii=False,
-            indent=4 if format else 0,
-            sort_keys=format)
-        return ('javascript', content)
-
-    def encode_sample_result(self, datatype, value, format=False):
-        r = tojson(datatype, value)
-        if self.nest_result:
-            r = {'result': r}
-        content = json.dumps(r, ensure_ascii=False,
-            indent=4 if format else 0,
-            sort_keys=format)
-        return ('javascript', content)
-
-
-def get_format():
-    return RestJson()
-
-
 def parse(s, datatypes, bodyarg):
     if hasattr(s, 'read'):
         jdata = json.load(s)
@@ -263,18 +202,47 @@ def parse(s, datatypes, bodyarg):
         kw = {argname: fromjson(datatypes[argname], jdata)}
     else:
         kw = {}
-        for key, datatype in datatypes.items():
-            if key in jdata:
-                kw[key] = fromjson(datatype, jdata[key])
+        for key in jdata:
+            if key not in datatypes:
+                raise UnknownArgument(key)
+            kw[key] = fromjson(datatypes[key], jdata[key])
     return kw
 
 
-def tostring(value, datatype, attrname=None):
+def encode_result(value, datatype, **options):
     jsondata = tojson(datatype, value)
-    if attrname is not None:
-        jsondata = {attrname: jsondata}
-    return json.dumps(tojson(datatype, value))
+    if options.get('nest_result', False):
+        jsondata = {options.get('nested_result_attrname', 'result'): jsondata}
+    return json.dumps(jsondata)
 
 
 def encode_error(context, errordetail):
     return json.dumps(errordetail)
+
+
+def encode_sample_value(datatype, value, format=False):
+    r = tojson(datatype, value)
+    content = json.dumps(r, ensure_ascii=False,
+        indent=4 if format else 0,
+        sort_keys=format)
+    return ('javascript', content)
+
+
+def encode_sample_params(params, format=False):
+    kw = {}
+    for name, datatype, value in params:
+        kw[name] = tojson(datatype, value)
+    content = json.dumps(kw, ensure_ascii=False,
+        indent=4 if format else 0,
+        sort_keys=format)
+    return ('javascript', content)
+
+
+def encode_sample_result(datatype, value, format=False):
+    r = tojson(datatype, value)
+    #if self.nest_result:
+        #r = {'result': r}
+    content = json.dumps(r, ensure_ascii=False,
+        indent=4 if format else 0,
+        sort_keys=format)
+    return ('javascript', content)
diff --git a/wsme/rest/protocol.py b/wsme/rest/protocol.py
index 2fe6c39..769dda9 100644
--- a/wsme/rest/protocol.py
+++ b/wsme/rest/protocol.py
@@ -60,6 +60,9 @@ class RestProtocol(Protocol):
                     outformat = df
 
         context.outformat = outformat
+        context.outformat_options = {
+            'nest_result': getattr(self, 'nest_result', False)
+        }
         yield context
 
     def extract_path(self, context):
@@ -150,8 +153,9 @@ class RestProtocol(Protocol):
         return kw
 
     def encode_result(self, context, result):
-        out = context.outformat.tostring(
-            result, context.funcdef.return_type
+        out = context.outformat.encode_result(
+            result, context.funcdef.return_type,
+            **context.outformat_options
         )
         return out
 
diff --git a/wsme/rest/xml.py b/wsme/rest/xml.py
index 00aa6f2..90f156d 100644
--- a/wsme/rest/xml.py
+++ b/wsme/rest/xml.py
@@ -224,73 +224,6 @@ def datetime_fromxml(datatype, element):
     return datetime.datetime.strptime(element.text, '%Y-%m-%dT%H:%M:%S')
 
 
-class RestXmlProtocol(RestProtocol):
-    """
-    REST+XML protocol.
-
-    .. autoattribute:: name
-    .. autoattribute:: dataformat
-    .. autoattribute:: content_types
-    """
-    name = 'restxml'
-    displayname = 'REST+Xml'
-    dataformat = 'xml'
-    content_types = ['text/xml']
-
-    def decode_arg(self, value, arg):
-        return fromxml(arg.datatype, value)
-
-    def parse_arg(self, name, value):
-        return et.fromstring(u("<%s>%s</%s>") % (name, value, name))
-
-    def parse_args(self, body):
-        return dict((sub.tag, sub) for sub in et.fromstring(body))
-
-    def encode_result(self, context, result):
-        return et.tostring(
-            toxml(context.funcdef.return_type, 'result', result))
-
-
-class RestXml(object):
-    name = 'xml'
-    content_type = 'text/xml'
-
-    def encode_error(self, context, errordetail):
-        el = et.Element('error')
-        et.SubElement(el, 'faultcode').text = errordetail['faultcode']
-        et.SubElement(el, 'faultstring').text = errordetail['faultstring']
-        if 'debuginfo' in errordetail:
-            et.SubElement(el, 'debuginfo').text = errordetail['debuginfo']
-        return et.tostring(el)
-
-    def encode_sample_value(self, datatype, value, format=False):
-        r = toxml(datatype, 'value', value)
-        if format:
-            xml_indent(r)
-        content = et.tostring(r)
-        return ('xml', content)
-
-    def encode_sample_params(self, params, format=False):
-        node = et.Element('parameters')
-        for name, datatype, value in params:
-            node.append(toxml(datatype, name, value))
-        if format:
-            xml_indent(node)
-        content = et.tostring(node)
-        return ('xml', content)
-
-    def encode_sample_result(self, datatype, value, format=False):
-        r = toxml(datatype, 'result', value)
-        if format:
-            xml_indent(r)
-        content = et.tostring(r)
-        return ('xml', content)
-
-
-def get_format():
-    return RestXml()
-
-
 def parse(s, datatypes, bodyarg):
     if hasattr(s, 'read'):
         tree = et.parse(s)
@@ -308,8 +241,10 @@ def parse(s, datatypes, bodyarg):
         return kw
 
 
-def tostring(value, datatype, attrname='result'):
-    return et.tostring(toxml(datatype, attrname, value))
+def encode_result(value, datatype, **options):
+    return et.tostring(toxml(
+        datatype, options.get('nested_result_attrname', 'result'), value
+    ))
 
 
 def encode_error(context, errordetail):
@@ -319,3 +254,29 @@ def encode_error(context, errordetail):
     if 'debuginfo' in errordetail:
         et.SubElement(el, 'debuginfo').text = errordetail['debuginfo']
     return et.tostring(el)
+
+
+def encode_sample_value(datatype, value, format=False):
+    r = toxml(datatype, 'value', value)
+    if format:
+        xml_indent(r)
+    content = et.tostring(r)
+    return ('xml', content)
+
+
+def encode_sample_params(params, format=False):
+    node = et.Element('parameters')
+    for name, datatype, value in params:
+        node.append(toxml(datatype, name, value))
+    if format:
+        xml_indent(node)
+    content = et.tostring(node)
+    return ('xml', content)
+
+
+def encode_sample_result(datatype, value, format=False):
+    r = toxml(datatype, 'result', value)
+    if format:
+        xml_indent(r)
+    content = et.tostring(r)
+    return ('xml', content)
diff --git a/wsme/tests/test_restjson.py b/wsme/tests/test_restjson.py
index b18bf41..90d7712 100644
--- a/wsme/tests/test_restjson.py
+++ b/wsme/tests/test_restjson.py
@@ -263,9 +263,6 @@ class TestRestJson(wsme.tests.protocol.ProtocolTestCase):
                 [int], {int: int}):
             assert fromjson(dt, None) is None
 
-    def test_parse_arg(self):
-        assert self.root.protocols[0].parse_arg('a', '5') == 5
-
     def test_nest_result(self):
         self.root.protocols[0].nest_result = True
         r = self.app.get('/returntypes/getint.json')
@@ -283,7 +280,7 @@ class TestRestJson(wsme.tests.protocol.ProtocolTestCase):
         v.aint = 4
         v.astr = 's'
 
-        r = self.root.protocols[0].encode_sample_value(MyType, v, True)
+        r = wsme.rest.json.encode_sample_value(MyType, v, True)
         print(r)
         assert r[0] == ('javascript')
         assert r[1] == json.dumps({'aint': 4, 'astr': 's'},
@@ -294,7 +291,7 @@ class TestRestJson(wsme.tests.protocol.ProtocolTestCase):
         assert tojson(wsme.types.bytes, b('ascii')) == u('ascii')
 
     def test_encode_sample_params(self):
-        r = self.root.protocols[0].encode_sample_params(
+        r = wsme.rest.json.encode_sample_params(
             [('a', int, 2)], True
         )
         assert r[0] == 'javascript', r[0]
@@ -303,19 +300,19 @@ class TestRestJson(wsme.tests.protocol.ProtocolTestCase):
 }''', r[1]
 
     def test_encode_sample_result(self):
-        r = self.root.protocols[0].encode_sample_result(
+        r = wsme.rest.json.encode_sample_result(
             int, 2, True
         )
         assert r[0] == 'javascript', r[0]
         assert r[1] == '''2'''
-        self.root.protocols[0].nest_result = True
-        r = self.root.protocols[0].encode_sample_result(
-            int, 2, True
-        )
-        assert r[0] == 'javascript', r[0]
-        assert r[1] == '''{
-    "result": 2
-}'''
+        #self.root.protocols[0].nest_result = True
+        #r = wsme.rest.json.encode_sample_result(
+            #int, 2, True
+        #)
+        #assert r[0] == 'javascript', r[0]
+        #assert r[1] == '''{
+    #"result": 2
+#}'''
 
     def test_PUT(self):
         data = {"id": 1, "name": u("test")}
diff --git a/wsme/tests/test_restxml.py b/wsme/tests/test_restxml.py
index 8af8150..982df7f 100644
--- a/wsme/tests/test_restxml.py
+++ b/wsme/tests/test_restxml.py
@@ -139,7 +139,7 @@ class TestRestXML(wsme.tests.protocol.ProtocolTestCase):
         value.aint = 5
         value.atext = u('test')
 
-        language, sample = self.root.protocols[0].encode_sample_value(
+        language, sample = wsme.rest.xml.encode_sample_value(
             MyType, value, True)
         print (language, sample)
 
@@ -150,13 +150,13 @@ class TestRestXML(wsme.tests.protocol.ProtocolTestCase):
 </value>""")
 
     def test_encode_sample_params(self):
-        lang, content = self.root.protocols[0].encode_sample_params(
+        lang, content = wsme.rest.xml.encode_sample_params(
             [('a', int, 2)], True)
         assert lang == 'xml', lang
         assert content == b('<parameters>\n  <a>2</a>\n</parameters>'), content
 
     def test_encode_sample_result(self):
-        lang, content = self.root.protocols[0].encode_sample_result(int, 2, True)
+        lang, content = wsme.rest.xml.encode_sample_result(int, 2, True)
         assert lang == 'xml', lang
         assert content == b('<result>2</result>'), content
 
@@ -183,8 +183,3 @@ class TestRestXML(wsme.tests.protocol.ProtocolTestCase):
 
         x = et.tostring(toxml(AType, 'value', AType()))
         assert x == b('<value />'), x
-
-    def test_parse_arg(self):
-        e = self.root.protocols[0].parse_arg('value', '5')
-        assert e.text == '5'
-        assert e.tag == 'value'